From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 9795 invoked by alias); 26 Jan 2012 01:34:24 -0000 Received: (qmail 9518 invoked by uid 22791); 26 Jan 2012 01:34:24 -0000 X-SWARE-Spam-Status: No, hits=-6.4 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_HI,SPF_HELO_PASS,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Thu, 26 Jan 2012 01:34:04 +0000 Received: from int-mx01.intmail.prod.int.phx2.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q0Q1Y1t2018826 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 25 Jan 2012 20:34:01 -0500 Received: from [10.3.113.84] (ovpn-113-84.phx2.redhat.com [10.3.113.84]) by int-mx01.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id q0Q1Y1pM024246; Wed, 25 Jan 2012 20:34:01 -0500 Message-ID: <4F20AD89.6010306@redhat.com> Date: Thu, 26 Jan 2012 01:34:00 -0000 From: Josh Stone User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:9.0) Gecko/20111222 Thunderbird/9.0 MIME-Version: 1.0 To: Chris Dunlop CC: "Frank Ch. Eigler" , systemtap@sourceware.org Subject: Re: Error removing module: Device or resource busy References: <4EF4E089.6060008@redhat.com> <20111225235927.GA2907@onthe.net.au> <4EF8BDF6.2070105@redhat.com> <20111228080728.GA12001@onthe.net.au> <4F1A1244.3010908@redhat.com> <20120121013535.GA8165@onthe.net.au> <20120121023012.GA8844@onthe.net.au> <4F1A68CB.8000409@redhat.com> <20120123072452.GA11940@onthe.net.au> <20120126002955.GA23432@onthe.net.au> In-Reply-To: <20120126002955.GA23432@onthe.net.au> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-IsSubscribed: yes Mailing-List: contact systemtap-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: systemtap-owner@sourceware.org X-SW-Source: 2012-q1/txt/msg00041.txt.bz2 On 01/25/2012 04:29 PM, Chris Dunlop wrote: >> Could you save/compare the same script compiled on one machine >> vs. the other, so we can try to figure out what makes the two >> gcc versions incompatible in this way? > > See below. Nothing too interesting in the text differences to my gcc-illiterate eye. [...] > +-DCC_HAVE_ASM_GOTO This is it. With that defined, jump_label.h defines HAVE_JUMP_LABEL, which enables this part of struct module in module.h: #ifdef HAVE_JUMP_LABEL struct jump_entry *jump_entries; unsigned int num_jump_entries; #endif Compiling with/without that means everything after is shifted, including the CONFIG_MODULE_UNLOAD stuff. You can also compare this with the dump given by dwarves pahole. It would probably work to just turn off CONFIG_JUMP_LABEL altogether, so it's not attempted on either compiler. I'd be worried about other hidden incompatibilities cropping up though. I don't see any other struct differences with pahole except jump_label stuff, but that doesn't comfort me much. So the easiest thing would be for you to compile the kernel with the target system's own compiler, so everything matches. :) If you keep the mismatch, we do have a couple of options to make it easier to compile stap modules on one and run on the other. One is the --use-server mode, where stap running on the target will query a network service running on the compile machine to build for it. The other is the --remote mode, where stap running on the compile machine will build the module locally, then send it over ssh to run on the target and collect the output. Josh